An electric-power supply produces electric-power and supplies the produced electric-power to a load directly connected thereto. An example of such an electric-power supply is an electric generator. When such an electric generator produces electric-power, a transformer transforms the electric-power into a voltage or current compliant with a load's resistance and supplies it to the load.
According to a conventional electric-power supply method, an independent power supply used a primary power supply directly supplies electric-power to a load. That is, the consumption power of the load is directly provided by the independent power supply.
As such, the conventional electric-power supply method has only used an independent power supply that directly supplies power to a load. That is, a method where electric-power provided from an independent power supply is amplified and then supplied to a load has not been known.
Therefore, before supplying electric-power from an independent power supply to a load, if it is amplified and then supplied to the load, the electric-power consumption can be reduced. That is, such idea becomes a landmark in the industry.